Biology Professor Jayne Yack’s latest research on insect communications was published in a leading science journal.
Some caterpillars drag their back ends along leaves to ward off intruders on their territory. Now it seems this “anal-scraping” – which creates warning vibrations – evolved from walking. It is the strongest evidence yet that communication signals can evolve from the exaggeration and repetition of routine behaviours.
Jayne Yack of Carleton University in Ottawa, Canada, and colleagues compared the genes of more than 30 species of caterpillar. They found that scrapers tended to be species that have evolved more recently, and that they settle disputes with an intruder without fighting. Instead they wiggle their rear, causing oar-like appendages to scrape and drum against the leaf below.
Crucially, both types of species moved their rear segments in an identical way when faced with an intruder. Non-scrapers have prolegs – a type of primitive limb – instead of oars, and the wiggle propels them forwards as they fight off an intruder. Yack says this suggests the oars evolved from prolegs, allowing new forms of communication to emerge – and both parties in a dispute to avoid injury.
Article:
http://www.nature.com/ncomms/journal/v1/n1/full/ncomms1002.html
http://www.newscientist.com/article/dn18760-talking-evolved-from-walking-in-caterpillars.html